The method and apparatus of this invention concern airport landing lights, and specifically a method and apparatus for aiming visual approach slope indicators which direct a beam of light at approaching aircraft to indicate to the pilot whether he is within the appropriate glide path which has been predetermined for aircraft approaching the particular runway. Such aircraft visual approach slope indicators are spaced intermittently along one or both sides of airport runways to aim narrow split beams of light, elongated in the horizontal plane, at approaching aircraft. Typically, the upper beam segment is white and the lower segment is red with the transition zone being pink. The farthest light unit of a two unit system, for example, is aligned and positioned so that the bottom of the red or lower segment is parallel to the glide path and forms the upper limit of the ideal glide path. In such a system, the light unit closest to approaching aircraft is aligned and positioned so that the top of the white or upper segment is aimed into the glide path and the bottom of the white segment is approximately parallel to the glide path and forms the lower limit of the ideal glide path. When an aircraft is on the proper glide path, the closest unit will appear white to the pilot and the farthest will appear red. If the approach is too high, both units will be seen as white and a low approach is indicated by both units appearing red.
Such visual approach slope indicators normally consist of a rectangular housing having adjustable legs at each corner so that the correct vertical angle of the narrow elongated light beam can be maintained by periodically verifying and adjusting the slope of the indicator housings. Previous alignment or aiming procedures employed an airplane flying the correct glide path as indicated by a person on the ground tracking the airplane. When the correct glide path was attained, the pilot would report any lights which were not properly visible and adjustments would be made on the spot by a third individual on the ground adjusting the legs of the various visual approach slope indicators. If the number of required adjustments consumed any considerable length of time, the airplane would be required to make a number of passes in order to provide the individual adjusting the indicator with sufficient time to complete the job. Such a procedure is obviously extremely time consuming and expensive in terms of personnel and equipment.